/*
 * Copyright 2010 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.netqin.authprotocal;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;

/**
 * A sample implementation of asynchronous API requests. This class provides the ability to execute
 * API methods and have the call return immediately, without blocking the calling thread. This is
 * necessary when accessing the API in the UI thread, for instance. The request response is returned
 * to the caller via a callback interface, which the developer must implement.
 * 
 * This sample implementation simply spawns a new thread for each request, and makes the API call
 * immediately. This may work in many applications, but more sophisticated users may re-implement
 * this behavior using a thread pool, a network thread, a request queue, or other mechanism.
 * Advanced functionality could be built, such as rate-limiting of requests, as per a specific
 * application's needs.
 * 
 * @see LogoutListener The callback interface.
 * 
 * @author Jim Brusstar (jimbru@fb.com), Yariv Sadan (yariv@fb.com), Luke Shepard (lshepard@fb.com)
 */
public class AsyncRunner {
    // Used as default activityCode by authorize(). See authorize() below.
    private static AuthorizationProtocol mAuthorizationProtocol;
    private static AsyncRunner sAsyncRunner;
    private String[] permissions = new String[] { "xmpp_login" };

    public static AsyncRunner getAsyncRunnerInstance(AuthorizationProtocol protocol) {
        mAuthorizationProtocol = protocol;
        if (sAsyncRunner == null) {
            sAsyncRunner = new AsyncRunner();
        }
        return sAsyncRunner;
    }

    private AsyncRunner() {
    }

    /**
     * Default authorize method. Grants only basic permissions.
     * 
     * @param dialogId
     *            显示进度的dialog id。仅showdialog，需要调用者关闭 See authorize() below for
     * @params.
     */
    public void authorize(Activity activity, final LoginListener listener) {
        authorize(activity, false, -1, Util.DEFAULT_AUTH_ACTIVITY_CODE, listener);
    }

    /**
     * Default authorize method. Grants only basic permissions.
     * 
     * @param dialogId
     *            显示进度的dialog id。仅showdialog，需要调用者关闭 See authorize() below for
     * @params.
     */
    public void authorize(Activity activity, boolean facebookNeedReAuth, int dialogId, final LoginListener listener) {
        authorize(activity, facebookNeedReAuth, dialogId, Util.DEFAULT_AUTH_ACTIVITY_CODE, listener);
    }

    public void authorize(Activity activity, boolean facebookNeedReAuth, int dialogId, int activityCode, final LoginListener listener) {
        if (mAuthorizationProtocol != null) {
            mAuthorizationProtocol.authorize(activity, facebookNeedReAuth, dialogId, permissions, activityCode, listener);
        }
    }

    /**
     * Invalidate the current user session by removing the access token in memory, clearing the
     * browser cookies, and calling auth.expireSession through the API. The application will be
     * notified when logout is complete via the callback interface.
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * @param context
     *            The Android context in which the logout should be called: it should be the same
     *            context in which the login occurred in order to clear any stored cookies
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void logout(final Context context, final LogoutListener listener, final Object state) {
        new Thread() {
            @Override
            public void run() {
                try {
                    String response = mAuthorizationProtocol.logout(context);
                    if (response.length() == 0 || response.equals("false")) {
                        listener.onAuthorizationProtocolError(new AuthorizationError("auth.expireSession failed"), state);
                        return;
                    }
                    listener.onComplete(response, state);
                } catch (FileNotFoundException e) {
                    listener.onFileNotFoundException(e, state);
                } catch (MalformedURLException e) {
                    listener.onMalformedURLException(e, state);
                } catch (IOException e) {
                    listener.onIOException(e, state);
                }
            }
        }.start();
    }

    public void logout(final Context context, final LogoutListener listener) {
        logout(context, listener, /* state */null);
    }

    /**
     * Make a request to Facebook's old (pre-graph) API with the given parameters. One of the
     * parameter keys must be "method" and its value should be a valid REST server API method.
     * 
     * See http://developers.facebook.com/docs/reference/rest/
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * Example: <code>
     *  Bundle parameters = new Bundle();
     *  parameters.putString("method", "auth.expireSession", new Listener());
     *  String response = request(parameters);
     * </code>
     * 
     * @param parameters
     *            Key-value pairs of parameters to the request. Refer to the documentation: one of
     *            the parameters must be "method".
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void request(Bundle parameters, LogoutListener listener, final Object state) {
        request(null, parameters, "GET", listener, state);
    }

    public void request(Bundle parameters, LogoutListener listener) {
        request(null, parameters, "GET", listener, /* state */null);
    }

    /**
     * Make a request to the Facebook Graph API without any parameters.
     * 
     * See http://developers.facebook.com/docs/api
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * @param graphPath
     *            Path to resource in the Facebook graph, e.g., to fetch data about the currently
     *            logged authenticated user, provide "me", which will fetch
     *            http://graph.facebook.com/me
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void request(String graphPath, LogoutListener listener, final Object state) {
        request(graphPath, new Bundle(), "GET", listener, state);
    }

    public void request(String graphPath, LogoutListener listener) {
        request(graphPath, new Bundle(), "GET", listener, /* state */null);
    }

    /**
     * Make a request to the Facebook Graph API with the given string parameters using an HTTP GET
     * (default method).
     * 
     * See http://developers.facebook.com/docs/api
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * @param graphPath
     *            Path to resource in the Facebook graph, e.g., to fetch data about the currently
     *            logged authenticated user, provide "me", which will fetch
     *            http://graph.facebook.com/me
     * @param parameters
     *            key-value string parameters, e.g. the path "search" with parameters "q" :
     *            "facebook" would produce a query for the following graph resource:
     *            https://graph.facebook.com/search?q=facebook
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void request(String graphPath, Bundle parameters, LogoutListener listener, final Object state) {
        request(graphPath, parameters, "GET", listener, state);
    }

    public void request(String graphPath, Bundle parameters, LogoutListener listener) {
        request(graphPath, parameters, "GET", listener, /* state */null);
    }

    public void request(String graphPath, Bundle parameters, RequestListener listener) {
        request(graphPath, parameters, "GET", listener, /* state */null);
    }

    /**
     * Make a request to the Facebook Graph API with the given HTTP method and string parameters.
     * Note that binary data parameters (e.g. pictures) are not yet supported by this helper
     * function.
     * 
     * See http://developers.facebook.com/docs/api
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * @param graphPath
     *            Path to resource in the Facebook graph, e.g., to fetch data about the currently
     *            logged authenticated user, provide "me", which will fetch
     *            http://graph.facebook.com/me
     * @param parameters
     *            key-value string parameters, e.g. the path "search" with parameters {"q" :
     *            "facebook"} would produce a query for the following graph resource:
     *            https://graph.facebook.com/search?q=facebook
     * @param httpMethod
     *            http verb, e.g. "POST", "DELETE"
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void request(
            final String graphPath, final Bundle parameters, final String httpMethod, final LogoutListener listener, final Object state) {
        new Thread() {
            @Override
            public void run() {
                try {
                    String resp = mAuthorizationProtocol.request(graphPath, parameters, httpMethod);
                    listener.onComplete(resp, state);
                } catch (FileNotFoundException e) {
                    listener.onFileNotFoundException(e, state);
                } catch (MalformedURLException e) {
                    listener.onMalformedURLException(e, state);
                } catch (IOException e) {
                    listener.onIOException(e, state);
                }
            }
        }.start();
    }

    /**
     * Make a request to the Facebook Graph API with the given HTTP method and string parameters.
     * Note that binary data parameters (e.g. pictures) are not yet supported by this helper
     * function.
     * 
     * See http://developers.facebook.com/docs/api
     * 
     * Note that this method is asynchronous and the callback will be invoked in a background
     * thread; operations that affect the UI will need to be posted to the UI thread or an
     * appropriate handler.
     * 
     * @param graphPath
     *            Path to resource in the Facebook graph, e.g., to fetch data about the currently
     *            logged authenticated user, provide "me", which will fetch
     *            http://graph.facebook.com/me
     * @param parameters
     *            key-value string parameters, e.g. the path "search" with parameters {"q" :
     *            "facebook"} would produce a query for the following graph resource:
     *            https://graph.facebook.com/search?q=facebook
     * @param httpMethod
     *            http verb, e.g. "POST", "DELETE"
     * @param listener
     *            Callback interface to notify the application when the request has completed.
     * @param state
     *            An arbitrary object used to identify the request when it returns to the callback.
     *            This has no effect on the request itself.
     */
    public void request(
            final String graphPath, final Bundle parameters, final String httpMethod, final RequestListener listener, final Object state) {
        new Thread() {
            @Override
            public void run() {
                try {
                    String resp = mAuthorizationProtocol.request(graphPath, parameters, httpMethod);
                    listener.onComplete(resp, state);
                } catch (FileNotFoundException e) {
                    listener.onFileNotFoundException(e, state);
                } catch (MalformedURLException e) {
                    listener.onMalformedURLException(e, state);
                } catch (IOException e) {
                    listener.onIOException(e, state);
                }
            }
        }.start();
    }

    /**
     * Callback interface for API requests.
     * 
     * Each method includes a 'state' parameter that identifies the calling request. It will be set
     * to the value passed when originally calling the request method, or null if none was passed.
     */
    public static interface RequestListener {

        /**
         * Called when a request completes with the given response.
         * 
         * Executed by a background thread: do not update the UI in this method.
         */
        public void onComplete(String response, Object state);

        /**
         * Called when a request has a network or request error.
         * 
         * Executed by a background thread: do not update the UI in this method.
         */
        public void onIOException(IOException e, Object state);

        /**
         * Called when a request fails because the requested resource is invalid or does not exist.
         * 
         * Executed by a background thread: do not update the UI in this method.
         */
        public void onFileNotFoundException(FileNotFoundException e, Object state);

        /**
         * Called if an invalid graph path is provided (which may result in a malformed URL).
         * 
         * Executed by a background thread: do not update the UI in this method.
         */
        public void onMalformedURLException(MalformedURLException e, Object state);

        /**
         * Called when the server-side Facebook method fails.
         * 
         * Executed by a background thread: do not update the UI in this method.
         */
        public void onFacebookError(FacebookError e, Object state);

    }
}
